1. Technical Field
The present invention refers to an aerial-supported procedure for the exploration of hydrocarbon deposits, especially crude oil and gas deposits, using fluorescence procedures, including aerial-supported geo-referencing of the detected locations by means of a digital terrain model, employing biosensors which are sensitive to hydrocarbons.
2. Description of Related Art
It is known that natural deposits of hydrocarbons, such as crude oil and gas deposits, have some natural escape of liquid or gaseous hydrocarbons to the surface. One basically distinguishes here between so-called micro seeps and macro seeps.
Macro seeps are essentially understood as natural outflows of liquid crude oil to the surface. Macro seeps mostly occur with deposits close to the surface. Since the times of the ancient Greeks and Romans, such macro seeps have served to make crude oil products. Later on, such visually detectable macro seeps have been used as indicators for crude oil deposits, in order to determine the locations for promising oil drillings.
Micro seeps are defined as smallest traces of hydrocarbons in liquid or gaseous form which rise to the surface from especially even deeper located deposits. Such micro seeps preferably occur where the geological structures facilitate the buoyancy of light hydrocarbons in permeable rocks, filled with fresh or salt water. The occurrence of micro seeps is not limited to the presence of such geological structures. Thus, micro seeps are also generated by diffusion processes, especially the short-time hydrocarbons. Under ideal conditions of a homogenous rock, a micro seep has a circular configuration with an increasing hydrocarbon concentration towards the centre of the circle.
For the exploration of macro seeps or oil pollutions on the water which have the same effect as macro seeps, a variety of aerial-supported exploration and detection methods are known. As examples therefore, just the visual detection and the sensor supported detection by means of a radar with lateral viewer, microwave radiometers, infrared/ultraviolet scanners and laser sensors have been used in the past. However, to detect macros seeps, these methods require a large quantity of oil on the surface for their detection.
Methods of detecting micro seeps are known which make use of micro-organisms. For example, U.S. Pat. No. 2,777,799 describes a method for the geo-microbial prospection of oil deposits, making use of the fact that certain natural micro-organisms are using short-time hydrocarbon compounds as an energy source. According to the procedure proposed in this patent, soil samples are taken close to the surface and exposed under laboratory conditions to an atmosphere containing oxygen and C14-marked hydrocarbons. After a sufficiently long incubation time, the metabolised C14-content is measured, allowing conclusions on the content of natural micro-organisms metabolising the hydrocarbons in the sample. The content of natural micro-organisms metabolising the hydrocarbons allows conclusions on the natural content of hydrocarbons in the soil at the location where the sample was taken and therefore an indication on possible micro seeps. The proposed procedure, however, shows up considerable disadvantages. The procedure requires a great deal of effort which results in a limited number of analyses of samples and therefore in a rough sample pattern. Micro-organisms which can use hydrocarbon compounds as an energy source are known from the following publications: Manfred Wagner et al., “Microbial prospection on oil and gas in East Germany, Yearbook of Geology A 149, page 287-309, Hanover 1998; as well as Sorkhon et al. (1995) “Establishment of oil-degrading bacteria associated with cyano-bacteria in oil-polluted soil”, J. Appl. Bacteriol, February; 78 (2): pp 194-9.
Moreover, it is known how to genetically manipulate appropriate micro-organisms in such a way that they produce fluorescence by means of a fluorescent protein when they absorb or come in contact with hydrocarbons. Respective processes for the manipulation of appropriate micro-organisms are state of the art in microbiology. So Figueira et al. (2000) describes such a bacterium in “Production of green fluorescent protein by methylotrophic bacterium extorquens”; FEMS Microbiology Letters, V 123, (2), pp. 195-200. Equally known are genetically manipulated micro-organisms, for example by Helinge, (2002) “Construction of fluorescent biosensor family”; Protein Science, pp. 2655-2875. However, heretofore, such biosensors have only been used in a laboratory setting and because sampling of a region is random, there is sporadic and limited information on the sampling area regarding the extent of deposits
With a view to the increasing exploration of hydrocarbon deposits, there is an urgent need for further exploration methods, especially for exploration methods which detect the above-mentioned micro seeps without the negative aspects of the heretofore methods of detection.